How to reproduce:
1. Open P4V client
2. Create a new user with a password "Pässword"
3. Connect to the Server in the P4V client
4. Create and open a new Unity project
5. Open Project Settings from Edit > Project Settings
6. Select the Version Control section
7. Fill in the required fields with correct data which was used in steps 2 and 3
Expected result: the connection is successful
Actual result: login fails due to the password being incorrect
Reproducible with: 2018.4.23f1, 2019.4.3f1, 2020.1.0b14, 2020.2.0a16
Notes:
-The Version Control settings are located in the Editor section of the Project Settings in earlier Unity versions
-Characters that were tested and turned out to be unsupported were: Ä, ä, ö, ü, ß, ą, ž, ł
-The P4V client itself doesn't seem to have any problems with the mentioned characters